A search engine may be used to locate information on the World Wide Web (Web). Search engines include databases that index words from pages or other documents on numerous Web sites. As is well known, a user enters a search term; the search engine searches its database for document(s) containing the search term; and the search engine displays a list of documents (e.g., hyperlinks) that contain those search terms.
Search engines use computer programs, such as robots, spiders and crawlers, to trace hyperlinks across the Web, and thereby populate their databases. When such computer programs move from one Web site to another, the programs index Web documents from various Web sites, and send the results back to a database. The database thus can become quite large. As a result, when a search term or keyword is entered into a search engine, the results of the search may include several thousand hyperlinks, or “hits”.
Web companies may incorporate content from advertisers in the results their search engines generate. An advertiser may, for instance, pay a search engine company to feature their content prominently in search results. A search engine may present paid listings on a results page in a format closely that resembles regular search results. Typically, these paid listings relate somehow to the initial search query (keyword(s)), and are returned based, in part, on the initial search query. It therefore behooves companies to incorporate search terms in their Web content that match keywords input to a search engine.